<!doctype html>
<html>
  <head>
    <title>屏幕适配</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
  </head>
  <body>
    <header>
      Navigation 导航
    </header>
    body 内容
    <footer>
      Footer links 页脚链接
    </footer>
  </body>
</html>